Neuropeptides and peptide hormones represent the largest class of chemical messengers that transmit information from one cell to another. In this review, several decades of research on peptides in cell-cell signaling are summarized, with a focus on neuropeptide discovery, biosynthesis, and function. In addition to covering the well-studied aspects of neuropeptides, emerging concepts are discussed, including classical versus non-classical neuropeptides and direct versus indirect neuropeptides. Other potential functions for peptides in intercellular and intracellular signaling are also discussed.

About the Author(s)

Lloyd D. Fricker, Albert Einstein College of MedicineDr. Lloyd Fricker received a Ph.D. from Johns Hopkins University School of Medicine in 1983 and obtained postdoctoral training at Oregon Health and Sciences University. He has directed a laboratory at Albert Einstein since 1986. While a graduate student, he discovered carboxypeptidase E, a key enzyme in the biosynthesis of most neuropeptides and peptide hormones (such as insulin). In addition to studies on carboxypeptidase E and neuropeptide production, his research group has discovered and characterized 12 additional members of the carboxypeptidase family, which perform diverse functions ranging from the production of growth factors to the processing of tubulin. Another set of studies in the Fricker Laboratory involves peptidomics, which uses mass spectrometry to identify and quantify peptides present in biological samples. Dr. Fricker has published 180 research articles and reviews in the field of peptides and peptide-processing enzymes.